scholarly journals Specific-Ion Effects Directed Noble Metal Aerogels: Versatile Manipulation for Electrocatalysis and Beyond

2019 ◽  
Author(s):  
RAN DU ◽  
YUE HU ◽  
René Hübner ◽  
Jan-Ole Joswig ◽  
Xuelin Fan ◽  
...  
Keyword(s):  
Porous Materials ◽  
Noble Metal ◽  
Noble Metals ◽  
Sol Gel ◽  
Synthetic Methods ◽  
Superior Performance ◽  
Gelation Mechanism ◽  
Practical Applications ◽  
Specific Ion Effects ◽  
Ion Effects

<div>Noble metal foams (NMFs) are a new class of functional porous materials featuring properties of both noble metals and monolithic porous materials, providing impressive prospects in catalysis, bio-sensing, plasmonic technologies, etc...Among reported synthetic methods to date, the sol-gel approach manifests overwhelming advantages for versatile synthesis of controlled nanostructured NMFs under mild condition. However, limited gelation methods and insufficient understanding of the underlying mechanism retards structure/composition manipulation of NMFs, hampering ondemand designing for practical applications. Herein highly tunable NMFs are fabricated at room temperature by activating specific-ion effects and regulating ion-nanoparticle interactions, affording various single/alloy NMFs with adjustable compositions (Au, Ag, Pd, Pt), ligament sizes (3.1~142.0 nm), and special morphologies. Their superior performance in programmable self-propulsion devices and electrocatalytic alcohol oxidation are demonstrated. This study provides not only a conceptually new route to fabricate and manipulate functional NMFs, but also an overall picture in understanding the gelation mechanism. It may pave the way for on-target designing versatile NMFs for various applications.</div>

scholarly journals Specific-Ion Effects Directed Noble Metal Aerogels: Versatile Manipulation for Electrocatalysis and Beyond

2019 ◽  
Author(s):  
RAN DU ◽  
YUE HU ◽  
René Hübner ◽  
Jan-Ole Joswig ◽  
Xuelin Fan ◽  
...  
Keyword(s):  
Porous Materials ◽  
Noble Metal ◽  
Noble Metals ◽  
Sol Gel ◽  
Synthetic Methods ◽  
Superior Performance ◽  
Gelation Mechanism ◽  
Practical Applications ◽  
Specific Ion Effects ◽  
Ion Effects

<div>Noble metal foams (NMFs) are a new class of functional porous materials featuring properties of both noble metals and monolithic porous materials, providing impressive prospects in catalysis, bio-sensing, plasmonic technologies, etc...Among reported synthetic methods to date, the sol-gel approach manifests overwhelming advantages for versatile synthesis of controlled nanostructured NMFs under mild condition. However, limited gelation methods and insufficient understanding of the underlying mechanism retards structure/composition manipulation of NMFs, hampering ondemand designing for practical applications. Herein highly tunable NMFs are fabricated at room temperature by activating specific-ion effects and regulating ion-nanoparticle interactions, affording various single/alloy NMFs with adjustable compositions (Au, Ag, Pd, Pt), ligament sizes (3.1~142.0 nm), and special morphologies. Their superior performance in programmable self-propulsion devices and electrocatalytic alcohol oxidation are demonstrated. This study provides not only a conceptually new route to fabricate and manipulate functional NMFs, but also an overall picture in understanding the gelation mechanism. It may pave the way for on-target designing versatile NMFs for various applications.</div>

scholarly journals Specific-Ion Effects Directed Noble Metal Aerogels: Versatile Manipulation for Electrocatalysis and Beyond

2019 ◽  
Author(s):  
RAN DU ◽  
YUE HU ◽  
René Hübner ◽  
Jan-Ole Joswig ◽  
Xuelin Fan ◽  
...  
Keyword(s):  
Porous Materials ◽  
Noble Metal ◽  
Noble Metals ◽  
Sol Gel ◽  
Synthetic Methods ◽  
Superior Performance ◽  
Gelation Mechanism ◽  
Practical Applications ◽  
Specific Ion Effects ◽  
Ion Effects

<div>Noble metal foams (NMFs) are a new class of functional porous materials featuring properties of both noble metals and monolithic porous materials, providing impressive prospects in catalysis, bio-sensing, plasmonic technologies, etc...Among reported synthetic methods to date, the sol-gel approach manifests overwhelming advantages for versatile synthesis of controlled nanostructured NMFs under mild condition. However, limited gelation methods and insufficient understanding of the underlying mechanism retards structure/composition manipulation of NMFs, hampering ondemand designing for practical applications. Herein highly tunable NMFs are fabricated at room temperature by activating specific-ion effects and regulating ion-nanoparticle interactions, affording various single/alloy NMFs with adjustable compositions (Au, Ag, Pd, Pt), ligament sizes (3.1~142.0 nm), and special morphologies. Their superior performance in programmable self-propulsion devices and electrocatalytic alcohol oxidation are demonstrated. This study provides not only a conceptually new route to fabricate and manipulate functional NMFs, but also an overall picture in understanding the gelation mechanism. It may pave the way for on-target designing versatile NMFs for various applications.</div>

scholarly journals Specific ion effects directed noble metal aerogels: Versatile manipulation for electrocatalysis and beyond

2019 ◽  
Vol 5 (5) ◽  
pp. eaaw4590 ◽  
Author(s):  
Ran Du ◽  
Yue Hu ◽  
René Hübner ◽  
Jan-Ole Joswig ◽  
Xuelin Fan ◽  
...  
Keyword(s):  
Noble Metal ◽  
Noble Metals ◽  
Sol Gel ◽  
Functional Materials ◽  
Synthetic Methods ◽  
Superior Performance ◽  
Formation Mechanisms ◽  
Gelation Mechanism ◽  
Specific Ion Effects ◽  
Ion Effects

Noble metal foams (NMFs) are a new class of functional materials featuring properties of both noble metals and monolithic porous materials, providing impressive prospects in diverse fields. Among reported synthetic methods, the sol-gel approach manifests overwhelming advantages for versatile synthesis of nanostructured NMFs (i.e., noble metal aerogels) under mild conditions. However, limited gelation methods and elusive formation mechanisms retard structure/composition manipulation, hampering on-demand design for practical applications. Here, highly tunable NMFs are fabricated by activating specific ion effects, enabling various single/alloy aerogels with adjustable composition (Au, Ag, Pd, and Pt), ligament sizes (3.1 to 142.0 nm), and special morphologies. Their superior performance in programmable self-propulsion devices and electrocatalytic alcohol oxidation is also demonstrated. This study provides a conceptually new approach to fabricate and manipulate NMFs and an overall framework for understanding the gelation mechanism, paving the way for on-target design of NMFs and investigating structure-performance relationships for versatile applications.

Recent Developments on Noble Metal Based Microparticles for Their Applications in Organic Catalysis

2020 ◽  
Vol 24 (8) ◽  
pp. 855-869
Author(s):  
Jian-Long Liu ◽  
Bo Jiang ◽  
Guo-Zhi Han
Keyword(s):  
Noble Metal ◽  
Noble Metals ◽  
High Selectivity ◽  
Low Cost ◽  
Organic Chemical ◽  
Preparation Methods ◽  
Practical Applications ◽  
Organic Catalysis ◽  
Recent Developments ◽  
Catalytic Applications

Noble metal microparticles have been employed as desired catalysts for a number of classical organic chemical reactions due to their unique physicochemical properties. Currently, in order to obtain more benefits for practical applications such as low cost, easy separation and high selectivity, many efforts of scientists are devoted to constructing composite microparticles in which noble metals are coupled with other materials. In this paper, we summarize some recent research developments on noble metal based microparticles for their catalytic applications in organic synthesis. Among them, application of the gold and silver based microparticles is the focus of this paper for their relatively low cost and the diversity of preparation methods. Furthermore, the challenges and prospects of noble metal based microparticles for their applications in organic catalysis are also discussed.

scholarly journals Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

2014 ◽  
Vol 5 ◽  
pp. 2413-2423 ◽  
Author(s):  
Rudolf Herrmann ◽  
Markus Rennhak ◽  
Armin Reller
Keyword(s):  
Noble Metal ◽  
Noble Metals ◽  
Synthetic Methods ◽  
Noble Metal Nanoparticles ◽  
Synthesis And Characterization ◽  
Core Shell ◽  
Ceria Nanoparticles ◽  
Thiol Groups ◽  
Silica Core

The present review article covers work done in the cluster NPBIOMEM in the DFG priority programme SPP 1313 and focuses on synthesis and characterization of fluorescent silica and ceria nanoparticles. Synthetic methods for labelling of silica and polyorganosiloxane/silica core–shell nanoparticles with perylenediimide derivatives are described, as well as the modification of the shell with thiol groups. Photometric methods for the determination of the number of thiol groups and an estimate for the number of fluorescent molecules per nanoparticles, including a scattering correction, have been developed. Ceria nanoparticles decorated with noble metals (Pt, Pd, Rh) are models for the decomposition products of automobile catalytic converters which appear in the exhaust gases and finally interact with biological systems including humans. The control of the degree of agglomeration of small ceria nanoparticles is the basis for their synthesis. Almost monodisperse agglomerates (40 ± 4–260 ± 40 nm diameter) can be prepared and decorated with noble metal nanoparticles (2–5 nm diameter). Fluorescence labelling with ATTO 647N gave the model particles which are now under biophysical investigation.

scholarly journals A general synthesis approach for amorphous noble metal nanosheets

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Geng Wu ◽  
Xusheng Zheng ◽  
Peixin Cui ◽  
Hongyu Jiang ◽  
Xiaoqian Wang ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Noble Metal ◽  
Oxygen Evolution Reaction ◽  
Noble Metals ◽  
Superior Performance ◽  
Metal Nanostructures ◽  
Initial State ◽  
Hydrogen Electrode ◽  
X Ray Absorption

Abstract Noble metal nanomaterials have been widely used as catalysts. Common techniques for the synthesis of noble metal often result in crystalline nanostructures. The synthesis of amorphous noble metal nanostructures remains a substantial challenge. We present a general route for preparing dozens of different amorphous noble metal nanosheets with thickness less than 10 nm by directly annealing the mixture of metal acetylacetonate and alkali salts. Tuning atom arrangement of the noble metals enables to optimize their catalytic properties. Amorphous Ir nanosheets exhibit a superior performance for oxygen evolution reaction under acidic media, achieving 2.5-fold, 17.6-fold improvement in mass activity (at 1.53 V vs. reversible hydrogen electrode) over crystalline Ir nanosheets and commercial IrO2 catalyst, respectively. In situ X-ray absorption fine structure spectra indicate the valance state of Ir increased to less than + 4 during the oxygen evolution reaction process and recover to its initial state after the reaction.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

scholarly journals Yttrium Oxide Nanoparticle Synthesis: An Overview of Methods of Preparation and Biomedical Applications

2021 ◽  
Vol 11 (5) ◽  
pp. 2172
Author(s):  
Govindasamy Rajakumar ◽  
Lebao Mao ◽  
Ting Bao ◽  
Wei Wen ◽  
Shengfu Wang ◽  
...  
Keyword(s):  
Yttrium Oxide ◽  
Metal Oxide Nanoparticles ◽  
Sol Gel ◽  
Antioxidant Properties ◽  
Nanoparticle Synthesis ◽  
Synthetic Methods ◽  
Host Material ◽  
Solid State Reactions ◽  
Oxide Nanoparticles ◽  
Advantages And Disadvantages

Metal oxide nanoparticles demonstrate uniqueness in various technical applications due to their suitable physiochemical properties. In particular, yttrium oxide (Y2O3) nanoparticle is familiar for technical applications because of its higher dielectric constant and thermal stability. It is widely used as a host material for a variety of rare-earth dopants, biological imaging, and photodynamic therapies. Y2O3 has also been used as a polarizer, phosphor, laser host material, and in the optoelectronic fields for cancer therapy, biosensor, and bioimaging. Yttrium oxide nanoparticles have attractive antibacterial and antioxidant properties. This review focuses on the promising applications of Y2O3, its drawbacks, and its modifications. The synthetic methods of nanoparticles, such as sol-gel, emulsion, chemical methods, solid-state reactions, combustion, colloid reaction techniques, and hydrothermal processing, are recapitulated. Herein, we also discuss the advantages and disadvantages of Y2O3 NPs based biosensors that function through various detection modes including colorimetric, electrochemistry, and chemo luminescent regarding the detection of small organic chemicals, metal ions, and biomarkers.

Adsorption of the Gas Molecules (NH3, C2H6O, C3H6O, CO, H2S) on noble metal (Ag, Au, Pt, Pd, Ru)–Doped MoSe2 Monolayer: A First-Principles Study

2021 ◽  
Author(s):  
Lanjuan Zhou ◽  
Sujing Yu ◽  
Yan Yang ◽  
Qi Li ◽  
Tingting Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Noble Metal ◽  
First Principles ◽  
Density Functional ◽  
Noble Metals ◽  
Gas Sensing ◽  
Functional Theory ◽  
First Principles Study ◽  
Gas Molecules ◽  
Sensing Performance

In this paper, the effects of five noble metals (Au, Pt, Pd, Ag, Ru) doped MoSe2 on improving gas sensing performance were predicted through density functional theory (DFT) based on...

scholarly journals Consolidated bioprocessing of lignocellulose for production of glucaric acid by an artificial microbial consortium

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Chaofeng Li ◽  
Xiaofeng Lin ◽  
Xing Ling ◽  
Shuo Li ◽  
Hao Fang
Keyword(s):  
Acid Production ◽  
Microbial Consortium ◽  
Consolidated Bioprocessing ◽  
High Titer ◽  
Value Added ◽  
Superior Performance ◽  
Glucaric Acid ◽  
Practical Applications ◽  
Work Distribution ◽  
Rut C30

Abstract Background The biomanufacturing of d-glucaric acid has attracted increasing interest because it is one of the top value-added chemicals produced from biomass. Saccharomyces cerevisiae is regarded as an excellent host for d-glucaric acid production. Results The opi1 gene was knocked out because of its negative regulation on myo-inositol synthesis, which is the limiting step of d-glucaric acid production by S. cerevisiae. We then constructed the biosynthesis pathway of d-glucaric acid in S. cerevisiae INVSc1 opi1Δ and obtained two engineered strains, LGA-1 and LGA-C, producing record-breaking titers of d-glucaric acid: 9.53 ± 0.46 g/L and 11.21 ± 0.63 g/L d-glucaric acid from 30 g/L glucose and 10.8 g/L myo-inositol in fed-batch fermentation mode, respectively. However, LGA-1 was preferable because of its genetic stability and its superior performance in practical applications. There have been no reports on d-glucaric acid production from lignocellulose. Therefore, the biorefinery processes, including separated hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP) were investigated and compared. CBP using an artificial microbial consortium composed of Trichoderma reesei (T. reesei) Rut-C30 and S. cerevisiae LGA-1 was found to have relatively high d-glucaric acid titers and yields after 7 d of fermentation, 0.54 ± 0.12 g/L d-glucaric acid from 15 g/L Avicel and 0.45 ± 0.06 g/L d-glucaric acid from 15 g/L steam-exploded corn stover (SECS), respectively. In an attempt to design the microbial consortium for more efficient CBP, the team consisting of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be the best, with excellent work distribution and collaboration. Conclusions Two engineered S. cerevisiae strains, LGA-1 and LGA-C, with high titers of d-glucaric acid were obtained. This indicated that S. cerevisiae INVSc1 is an excellent host for d-glucaric acid production. Lignocellulose is a preferable substrate over myo-inositol. SHF, SSF, and CBP were studied, and CBP using an artificial microbial consortium of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be promising because of its relatively high titer and yield. T. reesei Rut-C30 and S. cerevisiae LGA-1were proven to be the best teammates for CBP. Further work should be done to improve the efficiency of this microbial consortium for d-glucaric acid production from lignocellulose.

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